This invention relates to cargo or bulk bags and more particularly to apparatus and methods for cleaning the dry materials residue from used cargo bags before their reuse.
Cargo bags of flexible material are well known for transport and storage of dry bulk materials. They are provided with an upper tubular fill opening and a lower tubular discharge opening and lifting loops to permit the bag to be supported while filling, transporting and dispensing the contents. The bags are made of sturdy materials to support the weight of the filled bag. They may be reused many times. Before refilling the bags, after use, they are generally cleaned of the residual bulk materials clinging to the external surfaces of the bag, since the bag must be shipped in interstate commerce. The soiled empty bags are collapsed into a small volume easily enclosed in a protective outer bag. In this form they are transportable to a cleaning station or the filling station, but the inner and outer surfaces are preferably cleaned before the bags are refilled to protect the public and workers.
In the usual cleaning practice, the empty bag is installed on a framework with an overhead air pressure supply attached to the input to inflate the bag. A worker then vacuums the top, sides and bottom of the inflated bag. In order to access the bottom of the bag after clamping the discharge tube to an air exhaust, the fill tube must be quite high above the floor. An elevated ramp or balcony must be provided to enable the worker to reach the upper portions of the suspended bag. It is quite labor intensive to climb up and down while attaching, vacuuming, and detaching the top of the bag. The whole point of cleaning and reusing a bag rather than disposing after a single use is cost savings. When the labor and space costs get too high, the cleaning option becomes less attractive.